RESUMEN
Long after the first reports on human autologous chondrocyte implantation (ACI) by Brittberg in 1994, the development of a so-called optimal technology for osteochondral tissue regeneration is still one of the most challenging issues in knee surgery. Although the short- and intermediate-term results of ACI appear to be favorable, resources are being directed toward scaffold research to improve the technology. Scaffolds used for osteochondral repair may be either cell or noncell-based before its implantation in the knee. The characteristics that make scaffolds optimal for clinical use are that they be biocompatible, biodegradable, permeable, reproducible, mechanically stable, noncytotoxic, and capable of serving as a temporary support for the cells while allowing for eventual replacement by matrix components synthesized by the implanted cells. There is a growing interest in noncell and last-minute cell seeding technologies since they allow for a one-step surgery eliminating the morbidity and necessity of a previous chondral biopsy. Although clinical and histological results from many, already clinically available scaffolds seem to be promising, improvements throughout these technologies and the developments of new ones are still necessary to obtain a more efficient biological response as well as to improve the implant's stability. Moreover, as the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention should be directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only.
Asunto(s)
Materiales Biocompatibles , Enfermedades de los Cartílagos/terapia , Cartílago Articular , Artropatías/terapia , Articulación de la Rodilla , Andamios del Tejido , Enfermedades de los Cartílagos/patología , Condrocitos/trasplante , Humanos , Artropatías/patología , Andamios del Tejido/tendenciasRESUMEN
PURPOSE: To present our short-term experience with an osteochondral scaffold plug (TruFit plug; Smith & Nephew, Andover, MA) for cartilage repair in the knee and, more importantly, to discuss our approach to treat early clinical failures. METHODS: Twenty patients were consecutively treated for their cartilage lesions with the plug technique. These patients were prospectively clinically evaluated at 6 and 12 months of follow-up. Magnetic resonance imaging (MRI) was used for morphologic analysis of the cartilage repair. Biopsy samples were taken from 3 cases during revision surgery, allowing histologic assessment of the repair tissue. RESULTS: The short-term clinical and MRI outcome of this pilot study are modest. No signs of deterioration of the repair tissue were observed. Of the 15 patients followed up during 1 year, 3 (20.0%) showed persistent clinical symptoms or even more clinical symptoms after insertion of the plug. These patients were considered as failures and therefore eligible for revision surgery. During revision surgery, the repair tissue was carefully removed. The remaining osteochondral defect was filled with autologous bone grafts. Immediate and persistent relief of symptoms was observed in all 3 patients. Histologic assessment of biopsy specimens taken during revision surgery showed fibrous vascularized repair tissue with the presence of foreign-body giant cells. CONCLUSIONS: The overall short-term clinical and MRI outcome of the osteochondral scaffold plug for cartilage repair in the knee is modest. In this pilot study a modest clinical improvement became apparent at 12 months of follow-up. MRI data showed no deterioration of the repair tissue. Of the 15 patients, 3 (20%) had persistent clinical symptoms after surgery. These patients were successfully treated with removal of the osteochondral plug remnants and the application of autologous bone grafts. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
Asunto(s)
Cartílago Articular/cirugía , Articulación de la Rodilla/cirugía , Procedimientos Ortopédicos/métodos , Prótesis e Implantes , Adolescente , Adulto , Biopsia , Cartílago Articular/lesiones , Cartílago Articular/patología , Femenino , Humanos , Artropatías/cirugía , Traumatismos de la Rodilla/cirugía , Articulación de la Rodilla/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Reoperación , Adulto JovenRESUMEN
PURPOSE: More and more orthopedic procedures are performed in an outpatient setting. A commonly used strategy in pain management is the intra-articular injection of local anesthetics. Recent attention has been drawn to their possible toxic effect on chondrocytes. Local anesthetics, and in particular Lidocaine, are also used for diagnostic joint infiltrations. A controlled laboratory study was performed to investigate the possible toxic effect of Lidocaine on human articular chondrocytes. METHODS: Mature human articular chondrocytes were harvested from the knees of human tissue donors or patients undergoing total knee replacement. The cells were exposed to Lidocaine 1 and 2% with and without epinephrine and to a saline 0.9% control group, with variable exposure times in different experiments. The activity and viability of the cells were assessed by lactate dehydrogenase activity, interleukin-6 production and a live/dead cell count. RESULTS: After a 1-h exposure, devastating results were seen for Lidocaine 1, 2 and 2% with epinephrine showing cell death rates of 91, 99 and 97%, respectively, compared with 26% in the saline control group (P-values of 0.004, 0.010, 0.006, respectively). Exposing the chondrocytes to a 50/50 mixture of culture medium and local anesthetics substantially decreased cytotoxicity but still showed high toxicity when compared with the saline group (90% dead cells for Lidocaine 2%, P = 0.047). Lidocaine also showed a time-dependent cytotoxicity with gradually more dead cells after exposure for 15, 30 or 60 min. CONCLUSION: In vitro, local anesthetics containing Lidocaine are significantly more toxic to mature human articular chondrocytes than a saline 0.9% control group. The effect of Lidocaine on the viability of human chondrocytes in vivo needs further investigation. However, based on our in vitro results, cautious use of intra-articular Lidocaine in clinical practice is recommended.
Asunto(s)
Anestésicos Locales/toxicidad , Condrocitos/efectos de los fármacos , Lidocaína/toxicidad , Anciano , Supervivencia Celular/efectos de los fármacos , Condrocitos/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Técnicas In Vitro , Interleucina-6/metabolismo , Lactato Deshidrogenasas/metabolismo , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de TiempoRESUMEN
OBJECTIVE: To create scaffolds with silkworm cocoon, spider egg sac and spider dragline silk fibres and examine their use for chondrocyte attachment and support. METHODS: Three different kinds of scaffolds were developed with Bombyx mori cocoon, Araneus diadematus egg sac and dragline silk fibres. The attachment of human articular cartilage cells were investigated on these bioprotein matrices. The chondrocytes produced an extracellular matrix which was studied by immunostaining. Moreover, the compression behaviour in relation to the porosity was studied. RESULTS: The compression modulus of a silkworm silk scaffold was related to its porosity. Chondrocytes were able to attach and to grow on the different fibres and in the scaffolds for several weeks while producing extracellular matrix products. CONCLUSION: Porous scaffolds can be made out of silkworm and spider silk for cartilage regeneration. Mechanical properties are related to porosity and pore size of the construct. Cell spreading and cell expression depended on the porosity and pore-size.
Asunto(s)
Bombyx/metabolismo , Condrocitos/metabolismo , Seda/metabolismo , Arañas/metabolismo , Andamios del Tejido/química , Agrecanos/metabolismo , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Cartílago Articular/citología , Células Cultivadas , Colágeno Tipo I/metabolismo , Colágeno Tipo II/metabolismo , Matriz Extracelular/metabolismo , Fibroínas/metabolismo , Fibroínas/ultraestructura , Humanos , Inmunohistoquímica , Ensayo de Materiales , Microscopía Electrónica de Rastreo , PorosidadRESUMEN
Meniscal allograft transplantation was introduced into clinical practice now over 20 years ago for the treatment of the symptomatic postmeniscectomy patient who has not yet developed osteoarthritis. Over the years, the indications have been fine-tuned and certain risk factors for failure have been identified. As the number of publications increases steadily, we now know that meniscal allografting significantly reduces pain and improves function. Recent data also suggest a potential chondroprotective effect in a subpopulation of patients. However, the major drawback in all meniscus allograft studies is the general lack of a control population. To improve our knowledge, future prospective studies should include objective outcome tools to evaluate the status of the allograft in addition to the clinical scoring systems. Future research should focus to elucidate the biologic and cellular processes involved in graft repopulation and remodelation.
Asunto(s)
Traumatismos en Atletas/cirugía , Traumatismos de la Rodilla/cirugía , Meniscos Tibiales/trasplante , Trasplante de Tejidos , Humanos , Trasplante Homólogo , Resultado del TratamientoRESUMEN
Long-term data on the clinical outcome and the fate of the meniscus allograft after transplantation are scarce. In this study we present the clinical, radiological and MRI outcome of the meniscus graft and the articular cartilage after 42 meniscus allograft transplantations in 41 patients with a minimum follow-up of 10 years. A total of 27 medial and 15 lateral meniscal allografts were transplanted. Eleven of the medial allograft procedures were associated with a high tibial osteotomy. The patients were evaluated clinically at the time of transplantation and at the final follow-up using the modified HSS scoring system. The knee injury and osteoarthritis outcome score (KOOS) was used as an evaluation tool for patient-related outcome at the final follow-up. Joint space width narrowing and Fairbank changes were radiological outcome parameters, which were available for 32 patients. Femoral and tibial cartilage degeneration, graft extrusion and signal intensity were scored on MRI scans obtained in 17 patients approximately 1 year after transplantation and at the final follow-up (>10 years). For statistical analysis the patients were divided into three groups: lateral meniscal allograft (LMT), medial meniscal allograft transplantation with a high tibial osteotomy (MMT+HTO) and without (MMT). The modified HSS score revealed a significant improvement in pain and function at the final follow-up for all groups. Further analysis also revealed that an MMT+HTO procedure resulted in a greater improvement at the final follow-up when compared to MMT. Nonetheless, the KOOS scores obtained at the final follow-up revealed the presence of substantial disability and symptoms, in addition to a reduced quality of life. Radiographical analysis revealed no further joint space narrowing in 13/32 knees (41%). Fairbank changes remained stable in 9/32 knees (28%). MRI analysis showed no progression of cartilage degeneration in 6/17 knees (35%). An increased signal intensity of the allograft was present, as was partial graft extrusion in the majority of patients at the final follow-up. Seven cases had to be converted to a total knee arthroplasty during the follow-up; the overall failure rate was 18%. Long-term results after viable meniscus allograft transplantation are encouraging in terms of pain relief and improvement of function. Despite this significant improvement, substantial disability and symptoms were present in all investigated subgroups. Progression of further cartilage degeneration or joint space narrowing was absent in a considerable number of cases, indicating a potential chondroprotective effect. Level of evidence is therapeutic study, Level IV and retrospective analysis of prospectively collected data.